18 



PRELIMINARY NOTICE ON THE 



The accompanying diagram, prepared by Mr. W. F. Blanford, will 

 exhibit these reactions : — 



Oxygen of Air 



Charcoal 



Carbonic Acid 

 Cor CO, 



Slag. 



( Oxygen 



I Protoxide of ^ ^ Protexidel of Iron. 



> Iron ^2 O^yS*''^ 



^ t ( Iron. 



Ore = ■{ 



I 

 (^Peroxide of Iron 



The iron thus produced by this first process has never been thoroughly 



Character of iron from ^''^^^- ^* ^^ ^'^**^«' "^i^^g ^^^i^fly tO the impuri- 



first melting. ^jes mixed with it ; but these, by the continued 



exposure to the direct action of the blast in the open furnace in which 

 it is cleaned, are either melted or burnt out, and the repeated ham- 

 merings remove the impurities. 



Unfortunately, there have been no analyses of such products in 



this country sufficiently detailed, to enable a 

 No detailed analyses. 



sound opinion to be formed of the real composi- 

 tion of such slags, or impure metal, as I have spoken of A rude 

 analysis of slags resulting from similar processes, operating on very 

 similar, though not quite so siliceous, ores in Birbhoom, gave to Dr. 

 Macnamara* 55 per cent, of iron in the slag, with nearly 38 per cent, of 

 siliceous matter, together with a proportion of lime. 

 * Two specimens of slag were tested, and the results were : — 





Iron. 



Lime. 



Residue, chiefly 

 siliceous matter. 



No. 1, From Sandstone Ore, 



No. 2, „ Hematite, 



55-45 

 54-00 



6-18 

 8-43 



38-37 

 37-57 



MS. Beports, 



